Be Personally Offensive

It's not just about image; it's about behavior. You can be perfectly dressed for the job at hand but if you have a sewer mouth, make racist or sexist remarks, or stink like a goat, you're going to lose a lot of business. And if you actually urinate in a bucket in a customer's garage, as one garage door installer did in a televised episode of Marketplace, you might as well leave town.

In a time when everyone seems to have a phone sticking out of their pocket, there's no excuse for not answering a call, one way or another. Have your hands full of plywood sheeting or in a meeting with a client? That's what secretaries, answering machines, call forwarding or voice mail are for. Customers are not like your Mom; they're not going to keep calling even if you don't pick up because they’re worried about you. How to Answer the Phone Properly lays out the rules that everyone in your small business should be following.

Need to Use the Customer's Tools or Equipment

Showing up to clean gutters without your own ladder. Or showing up to install a floor and asking your customer if he has a saw you can borrow. You might as well just tattoo "fly by night" on your forehead and be done with it. People with real businesses and real expertise have their own tools.

Refuse to Listen to Clients or Customers

You may have years of experience and enough certifications and awards to paper a whole wall of your office, and certainly know best. So what? That's why they hired you and it may be why they fire you if they feel you're not hearing what they have to say and going to give them what they want. Sure, blue is the "in" color this year. But if the client wants green, listen and adapt.

Leave a Job Unfinished And/Or Don't Bother to Clean up After You’ve Done the Job

Do you expect a customer to be pleased with your work when the job isn't done? Do you think a customer will be sure to praise your work to all her friends when you've left debris all over their kitchen or lawn? Really? Not likely. Even when you're really pressed to get to the next job, you need to push down the feeling, rearrange your schedule and make sure you get the job in front of you done right first.

Not Try to Fix a Problem Related to Your Product And/Or Service

Sometimes problems are truly things that you can do nothing about. But you can still "show willing" and listen to the customer's complaint and, in the best case scenario, give them some action they can take, whether it be contacting the manufacturer or complaining to their municipality. If it's in your purview, though, you need to make it right, as Mike Holmes says. It's important in terms of future business and potential referrals.

Bring Dogs and Let Them Run Around the Customer's Yard And/Or House

Dogs are like children – not everyone loves them. Especially as dogs, unlike children, have some less than endearing habits such as pressing their noses into people’s crotches and defecating on people’s lawns. And customers may have allergies to dogs or pets of their own that are not compatible with yours. Never take your pet to a job site without having cleared it with the customer first.

Make Inaccurate Estimates

If you're not good at estimating how much a particular product or service will cost and/or how long it will take to finish a job or project, you really need to work on this skill. Your estimate is part of what will win you the work. Not being able to estimate the cost and time a job will take accurately breeds poor client relationships. Customers don't see it as you being inaccurate. They see it as you lying to them.

Send out an Assistant to Do Your Job

Always keep in mind that clients have hired you, not an assistant or underling. They want you working on their case or project or job. Depending on what you do, you can get away with having an assistant do some parts of a job as long as you clearly supervise that person and/or their work. But you can't send the assistant out to do your job and expect a client to be happy. And sending out a poorly trained or incompetent assistant is suicidal business-wise.

Be Incompetent – But Pretend Not to Be

Misrepresenting your credentials and/or your abilities is not only a quick way to run yourself out of business but may also lead to criminal charges or being sued. And it really doesn't matter whether or not you had good intentions and were "just trying to help someone out" and saving them the cost and trouble of calling in an electrician, a tiler, a drywaller etc. If you are not qualified to do something or have not done it before, you shouldn't be doing it.

How Did You Do?

If you've never done any of these things in the course of doing business, congratulations! Give yourself and your employees a pat on the back and keep right on doing what you do, creating and attracting even more happy customers.

Unfortunately, I bet that when you were reading through the list of bad practices, the names of different businesses that you have dealt with sprang to mind. If so, do those businesses a favor and let them know what they did poorly. Legitimate businesses are always looking to improve their customer service and their business practices.